Conventionally, a forced air cooling apparatus has a blower for creating cooling air that is forced to blow onto an electronic device operating within a casing or frame with walls. In the past, such an apparatus has been installed or mounted within the casing so that a distance between an air intake surface or structure at the inlet of the of the blower and a wall surface of the casing in which the blower is mounted is at least more than one half of a diameter of the inlet of the blower to thereby optimize the cooling ability obtained from the blower. For example, the invention disclosed in Japanese Patent Laid-Open No. 144600/1988 discloses such a conventional blower arrangement requiring above-mentioned separation distance for optimum performance.